With publishers craving stories about critters other than ‘the big two,’ writers crank out tales of life with hedgehogs, tarantulas and tree kangaroos.

In her book “How to Be a Good Creature,” Sy Montgomery gains rare insight into her late mother after a wild ermine rips the head off one of the author’s chickens.

“She was, in her way, as fierce as that ermine,” Ms. Montgomery writes in her memoir about lessons she has learned from 13 different animals. After seeing the voracious creature, she writes, her heart “flooded with the balm of forgiveness” for her mother.